Copolymerization of methyl acrylate with isobutylene in the presence of lewis acids

Abstract

The copolymerization of methyl acrylate (MA) and isobutylene (IB) in the presence of Lewis acids (EtAICI,, Et,AICI. Et3AI, AICI,, and ZnCI,) a t low Lewis acid/MA mole ratio was investigated. EtAICI, and Et,AICI were found to initiate the spontaneous reaction. An alternating copolymer was produced in this reaction when an excess of IB in the initial monomer feed was used. The copolymerization in the presence of Et,AI, AICI,, and ZnCI, did not proceed spontaneously and was initiated by dibenzoyl peroxide (BPO). In this case MA-rich copolymers are formed even in systems containing a large excess of IB in the monomer feed. The addition of BPO to systems containing ethylaluminium chlorides strongly diminishes the tendency towards alternating propagation. It was concluded that the mode of initiation has a significant influence on the copolymer composition. The alternating copolymerization by EtAIClz was studied in detail in order to determine the influence of the catalyst concentration, monomer feed ratio, reaction temperature and time on the monomer conversion, copolymer composition, molecular weight and tacticity. 0025-1 16X/82/05

Synthesis and Modeling of Polysiloxane-Based Salt-in-Polymer Electrolytes with Various Additives

“…19,20 The initial increase among the alumina-containing composites could be therefore due to the interaction of alumina with the salt to promote ion dissociation thus the number of free ions leading to an increase in conductivity to some extent. 25 On the other hand, the conductivity started decreasing again when 8 wt % alumina concentration was reached. This trend could be explained by a great increase in the interaction between ions and the surface of the fillers in addition to the adsorption like process taking place at the surface as reported by Liu, which is accompanied by an increase in lithium transference number.…”

“…For poly(ethylene oxide)-based polymer electrolyte composites, for example, a conductivity enhancement was obtained at around 10 wt % by many authors. [21][22][23][24][25][26] There is a common agreement that the conductivity is enhanced as polyether crystallinity is reduced; however, Wieczorek et al 19,20 reported a change in conductivity due to acid-base-type interactions involving polyether oxygens and filler acid or base centers.…”

“…18 Up to now, great efforts have been devoted to such composite polymer electrolytes to enhance the ionic conductivities. [19][20][21][22][23][24][25][26][27][28][29] Although a direct relation with increasing filler content was generally mentioned, the optimum concentration of this component varied over a wide range. For poly(ethylene oxide)-based polymer electrolyte composites, for example, a conductivity enhancement was obtained at around 10 wt % by many authors.…”

A study on LiBOB-based nanocomposite gel polymer electrolytes (NCGPE) for Lithium-ion batteries

“…Thus, search for the new type of salt is explored. In this regard, LiBOB salt has been identified as the more suitable salt because of its active participation for the formation of SEI and satisfying other basic requisites suggested for polymer electrolytes [5][6][7][8][9][10][11]. So, in the present work, LiBOB-based polymer nanocomposites has been studied to understand the suitability for lithium ion cells by ac impedance and phase morphological studies.…”

Salt-In-Polymer Electrolytes Based on Polysiloxanes for Lithium-Ion Cells: Ionic Transport and Electrochemical Stability

“…Afterwards in 1979 ARMAND et al proposed that polymer electrolytes based on PEO with incorporated lithium salts could be used for LIB (4). These SPEs have been extensively investigated during the last thirty years (5)(6)(7). In the literature there are several polymers which are derived from PEO, i.e.…”